import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';

class Echo extends StatelessWidget {
  final String text;
  final Color backgroundColor;

  const Echo({
    Key? key,
    required this.text,
    this.backgroundColor = Colors.grey,
  }) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Center(
      child: Container(
        color: backgroundColor,
        child: Text(text),
      ),
    );
  }
}

void main(){
  runApp(const Echo(text: "hello world"));
}